Furnace



Aug. 17,1926. 1,596,306 HxC, RENTSCHLER ETVAL FQRNACE Filed July 28, 1921 BY' ATTORNEY COOLING suitable material, but we Patented Aug.' 17, 1926.

UNITED STATES PATENT OFFICE.

HARVEY` CLAYTON RENTSCHLER AND JOHN WESLEY IMARDEN, OF EAST ORANGE, NEW JERSEY, ASSIGNORS WESTINGHOUSE LAM? COMPANY, A CORPORATION OF PENNSYLVANIA.

FUBNACE.

Application tiled `Tuly 28, 1921.

Uur invention relates to metallurgical furnaces and more particularly to electrical furnaces 1n which the material undergoing treatment assists in the operation of the,

furnace.

The subject matter of this invention is also disclosed but not claimed in an application filed by us, Serial No. 488,229, filed July Q8, 1921, on a process of manufacturing metals and their uses, and assigned to the same assignee as the present invention.

An object of our invention is to provide a furnace in which metallic and semi-metallic substances, which cannot at present be satisfactorily worked, may be heat treated to render them workable.

A further object is to provide a vacuum electrical furnace in which the material being treated is adapted to complete the electrical circuit.

Another object is to rovide a vacuum electrical furnace of simple design and economical construction.

Otherfobjects will be apparent from a reading of the followin description.

In making a series o experiments with the view of devising a satisfactory mode of treatment whereby certain substances, such as tungsten, molybdenum, chromium, zir-I conium, thorium, titanium, uraniunr, vana dium, tantalum, beryllium, etc., may be altered to such an extent that they may become malleable or even rendered ductile, we have devised a special type of furnace for use in connection therewith and which may metal urgical treatments of various natures.

The furnace or treating vessel we have de-VL vised operates on a different principle from any other of which we are aware` in that the material being heat treated. isumaintained in the highest attainable vacuum dur` ing the treatment. ABriefly stated, the furnace comprises a closed treating vessel or "envelope which may be termed a .treating bottle.` The bottle may be made of any y refer to employ a non-conducting materia such.y as .hard glass, which is capable of withstanding high temperatures. The bottle is hermetically sealed during the heat treatment* operation and has provision for facilitating the maintenance of a highvacuum therein during rove generally useful in conducting- Serial No. 488,230.

Referring now to the view shown in the y accompanying drawing, the embodiment of our invention illustrated thereby comprises a globular envelope or container 1 havin two diametrically opposed necks 2 and 3 which have flared recesses or openings 4 and 5 therein communicating with the interior of the envelope. rl`he envelope may be made of any suitable material which will maintain a vacuum created therein. `We prefer, however, as mentioned above, to em loy a hard glass capable of withstanding tlie range of temperatures to which the material under going treatment may be subjected. This envelope forms the main body of the treaty-- ing vessel or bottle and may be of any desired size.

Positioned intermediate the two necks 2 and 3, and preferably slightly closer to the neck 2, is a tube 6 which communicates with the interior of the vessel. This tube furnishes a convenient means for connecting the vessel to a diffusion pump (not shown) in order that a vacuum of high degree may be maintained within the vessel when the openings 4 and 5 are hermetically sealed.

In order to hermetically seal the envelope The against the entrance of any deleterious mat i ter, we prefer to provide each of the openings with sto y pers or electrodes, termed terminals, 7 an 8; Any desirable material or Astyle of stopper which will serve the purpose of conducting an electrical current to the interior of the vessel maybe employed. However, we have made use off.y iron Stoppers having chambers 9 and 11 therein for a purpose to be laterdescribed. The Stoppers should have a ground fit within the necks 2 and 3 and be slightl tapered inwardly to make a tighter fit. iquid cement or any incr desired material may be employed to malte the joint between these stop ers and the ivalls ot the vessel gastight. e have found, however, that a carefully ground joint iornis a hermetic seal.

The stoppers preferably have hollow nipples l2 and 13 which projectivithin the vessel in order to bring the material undergoing treatment u'ell within the vessel. l

Fitted within the chambers are covers 14 and l5 'Ver the openings thereto, and fastened within two openings in these covers or closures, are tivo pairs of pipes i6, 17, 18 and i9, the pipes 16 and 18 projecting but slightly 1ivitliin the chambers While the pi es 3.. and if) reach Well down Within the nipp es. Circilation of the Cooling medium to prevent overheating of the iron stoppers or e7 trodes may be had by appro riate coni neel/ron to the pipes from a suitab e circulatdevice (not shown).

The stoppeis are identical in structure with the exception that the upper stopper 1v be -providediwitli a clamping means f desirable structure by means' of within the container. lVe have einl a spring clamp 21 comprising a bolt engaging an opening 23 in an of the electrode 'i'. The bolt ,las tivo heads 25 and 26, the former engagan abutment 27 of the stopper 7 and latter preventing disengagement of the "rom its support. n. spring 28 mainead ci? the bolt in iirm engagetiie abutment :2T so that material between will be rigidly held ion Within the vessel. The provide-s a convenient means ng the insertion and removal steriai,

betr-veen the lower stopper or electhe material supported. by the up- .l 3de may be maintained by a pool idii the lower electrode and a clamp 59 secured to the lower end l being treated. The clamp a continuous circuit will ut may be conducted any appropriate source (not shown) by means Wires 3l and 32 which as follows: tungsten, molybdenum, irconiuim. thorium, titanium, medium, tantalum, beryllium, to the electrode 'i' by means The spring clip Q9 is placed eno., thus ensuring a firm curi;T or other' conducting material.

i that `when the material Contact. The stopper 7' is then sealed into ,the opening 4, after which the diffusion pump is operated until a high vacuum is produced within the vessel. Thereafter, the current is admitted to the material gradually and is increased until the value thereof is 8O or 90%, more or less, or' the lusion current. This current is maintained until the material is properly conditioned so that. thereafter, further mechanical treatment thereof will render it ductile. After the material has been heat-treated until it may be wrought, the current is reduced gradually to zero and the material removed. By fusion current, we mean that value of current required to melt off the bar when undergoing treatment. lt will be understood that many modifications of the above described apparatus may be made without departing from the spirit of our invention.

What is claimed is:

ljAdevice for heat-treating material, comprising an enclosing envelopehaving a plurality of openings, closures comprising electrodes fitted in the openings, a pool of electrically conductive liquid within said kenvelope and in which one of said electrodes is immersed, and means mounted on the other electrode for engaging the material to be heat-treated. l

' A device for heat-treating material comprising an enclosing envelope havin outwardly extending oppositely dispose necks, closures for said necks, said closures l constituting electrodes, a pool of electrically conductive liquid in said envelope and in which one of the electrodes is immersed, and means supported by the other electrode for pendently supporting the material to be heat-treated.

3. A device' for heat-treating material, comprising an enclosing envelope havinv a plurality of openings, Stoppers constituting electrodes for the openings, a ool of niercury immersing one of sai electrodes, means carried by the other electrode for pendently support-ing the material to be4 lent-treated, and means for cooling said' Stoppers.

4. A device for heat-treating material, comprising an enclosing envelope, a plurality of removable `electrodes in said envelope, a ool of mercury enveloping the inner end o ont of said electrodes, means carried by the other electrode for supporting the material to be heat-treated, and means for maintaining an electrical circuit between said mercury ool and an electrode through the material shrinks.

5. A heat-treating apparatus comprising a container having a plurality of openings, a conductive liquid in said container, a plurality of removal closures for the openings eing. heated When the latter in said container, one of said closures having its inner end immersed in said liquid, said closures constituting electrodes, means carried by one of said electrodes for securing thereto materials to be treated, means for maintaining contact between the material and the conductive liquid, and means for exhausting said container.

l6. A heat-treating apparatus comprisin a container having oppositely dispose openings therein, a hollow electrically conductive closure for each of the openings, means for circulating a cooling fluid within said closures, a conductive liquid pool, immersing the inner end of one of said closures, means carried by the other closure for supporting the material to be heated, means for maintainin the material in electrical circuit with said conducting liquid during gas-tight in two of said openings, and a tube connected to the remaining opening, means connected to said tube for evacuating the air and, occlnded gases from said vessel,

means connected to said Stoppers for pass- 30 ing an electric current therethrough when the material undergoing treatment is placed in circuit therewith and means for cooling said Stoppers.

In testimony whereof, we have hereunto 35 subscribed our names this 27th day of July 1921. c

HARVEY CLAYTON RENTSCHLElL JOHN WESLEY MARDEN.

three openings tlleref` in, Stoppers of con ucting material sealed 25 

